1. Field of the Invention
The present invention relates to the field of electromagnetically operated pneumatic poppet valves.
2. Prior Art
Poppet valves of various designs are well known in the prior art. Such valves are characterized by a valve member that is moveable in a direction generally perpendicular to the plane of a valve seat between a valve open position and a valve closed position. Of particular importance to the present invention are solenoid actuated poppet valves. Such valves have an actuator coil which when electrically energized, will move the valve member to the valve open (or closed) position, with a mechanical return spring returning the valve member to the valve closed (or open) position when the magnetic circuit is de-energized.
The configuration and construction of solenoid actuated poppet valves various widely dependent upon the intended application of the valves and various choices made during the valve design phase. However, two general forms of construction, either or both of which may be incorporated into a single valve design, are commonly used. In one conventional construction, various parts are threaded together or held together by complementary threaded members that in some cases allow for disassembly, reassembly, and even replacement of parts in the field. In another conventional construction, the various parts are contained within some encapsulating form of enclosure, configured in such a way as to be tamper-proof or not readily disassembled in the field. This latter construction is more commonly used in smaller poppet valves wherein the cost of repairing the same valve may exceed the cost of replacement. Still, such valves that do not pass final inspection in the manufacturing process can be disassembled at the factory for troubleshooting purposes, recovery of parts therein, etc.
The present invention is a poppet valve suitable for manufacture in miniature form and capable of very high speed operation wherein neither of the foregoing conventional constructions is practical due to the penalties the added mass required of a valve which may be disassembled impose on its response capability.
Valves suitable for manufacture as a miniature poppet valve are disclosed. The valves might include, minimally, an upper pole piece, a lower pole piece and an armature, all of magnetic material. The two pole pieces are permanently joined such as by a press fit, welding and/or by an adhesive to entrap an actuator coil and form the magnetic circuit for an armature assembled therein. A valve seat member is molded to, snaps or barbs onto the armature piece and is entrapped by the armature to complete the assembly. Use of intended permanent assemblies and use of the parts of the magnetic circuit as the valve outer housing or case allows realization of valves of smaller, lower mass and higher speed capability than could be practically provided using valves of other designs or using other assembly techniques.